Replacing a stock ECU with a used part pulled from a salvage----
 

Upfront Thanks for your input and opinions-If this turns into a bit of a rant I apologize.

Recently swapped an '04 ap2 engine into my 03 ap1. The current setup runs fine with the 03 ECU but I'd like to switch over to a 04 ECU. I'd much prefer to buy used with a part like this as I've got a good source.
I know that I've got a few options to make this work and am curious what other peoples experience has been (if there's been any ((I know ther has!)))

should I for example get the ECU, install it myself real quick at the dealer and have them rewrite it to my keys? How much should that cost generally at a dealership? My understanding is that the dealership is the only one who can do this, is that correct? Talked to a tech at the dealer and he made it sound like they had to do a bunch of stuff, sounded like b.s. to me.

should I get an ECU, key, and ignition switch from the same donor car and swap the parts and avoid the dealership all together?

should I get an ECU, and key from the same donor car- make a dummy key(without transponder) to still turn the ignition and keep the other key nearby to satisfy the immobilizer. Would that work? to just have the key that matches the ECU on my key chain while using a dummy key in the ignition or do you actually have to tape it to the other key like the service manual suggests for testing with a known good ECU? Could I use my regular key in the ignition with the key from the new ECU on my key chain?
would that satisfy the immobilizer?


Any input would be helpful

If you can, get the ecu with matching key as that is your best chance. It'll require a reprogram. I don't have any experience with it or the price.

Yea if I get the ECU with a key it'd for sure be from the same car and i'd be sure to get the vin#s as well.

Sorry I left out the VIN, but you'll need that also. That should take care of you minus paying.

I just had the ECU and had no issue.

Honda didn't need a vin or anything

They told me they read the key, read the old ecu, read the new ecu then reprogram the new ecu to match the old one.

$40 is all it cost me since I took the plastics off and had it ready to swap out.

thanks speedjunky and racer xl
to think the tech I spoke with at Honda implied it'd be a couple hours of labor. what a leech. I'm assuming when you say the reprogram the new ecu to match the old one you're simply referring to the immobilizer info right?

anyone else have experience with how much the reprogram should cost from Honda.

just get the ecu and have your dealer reprogram it to your key. It's better to keep the original key to the car in my opinion. To program the ecu should take about 20 minutes max. Price typically varies from dealer to dealer but I think I paid 40 to a small honda repair shop locally to do it.

Yup just the immobilizer is what can be programmed.

ok thanks dumped and speed junky. looks like $40 ballpark is what I should call around and look for if I bring it in with the plastics pulled so they have quick access.
I'm on it. Dumped- when you say a small honda repair shop are you talking a small dealership or a small shop that specializes in honda repairs?

all depends if they invested in the immobilizer tools or not only way to know is to call around.